Calutron face plate



2 Sheets-Sheet 1 Filed Oct. 8, 1946 K huh t //vv/v TOR WILL IAM M BROBECK A TTORNEY.

CALUTRON FACE PLATE Wiiliam M. Brubeck, Berkeley, Calif., assignor to the United States of America as represented by the United States Atomic Energy Commission Application October 8, 1946, Serial No. 701,912

3 Claims. (Cl. 250-419) The present invention relates to the apparatus for treating a polyisotopic substance to produce a plurality of segregable masses wherein the distribution of the constituent isotopes has been altered so that one of the masses produced is enriched with respect to at least one isotope. The purpose of such treatment is to obtain a product characterized by an enhancement of the percentage of a selected isotope. More specifically, the invention relates to a device known in the art as a calutron, a term whose definition is any apparatus or machine where isotope separation or enrichment is achieved on a large scale yielding commercially useful quantities of one or more isotopes, by appropriate separative action on gaseous ions with electrostatic or electromagnetic means or combinations of them.

The foregoing definition has been taken from US Patent 2,709,222, which issued to Ernest 0. Lawrence, on May 24, 1955. In that patent, the theory of isotopic separation and the principles of operation of a calutron are fully set forth, and will not here be repeated.

It may be stated generally, however, that the calutron to which this invention relates comprises: essentially an evacuated tank disposed in a strong, substantially uniform magnetic field, and a transmitter and a receiver located within the tank.

The transmitter includes an ionizing arc chamber having an electron emitting cathode associated therewith. The are chamber has an exit slit opening out into the tank, and spaced from the slit are two mutually spaced accelerating electrodes carried at a relatively high negative potential with respect to the arc chamber. As a result of this potential difference, positive ions formed in the arc chamber are drawn out through the slit, and are projected in a slightly divergent beam into the tank.

A continuous supply of material, the isotopes of which are to be separated, is provided in the arc chamber. This may conveniently be accomplished by providing a charge reservoir in communication with the arc chamber, and the material or a suitable compound thereof may be provided in the charge reservoir. The charge material may then be heated, and its vapor caused to flow at a controlled rate into the arc chamber, where ions of the several isotopes are formed and projected into the beam previously described.

The calutron described herein is particularly useful in the separation of U and U and a suitable charge material for this separation is UCl a solid which may be caused to pass into the vapor phase, by heating the compound in the charge reservoir. Alternatively, of course, the charge material may be a compound which is a gas at normal conditions and is supplied directly to the arc chamber at a controlled rate.

The beam of positive ions of the polyisotopic substance is projected through the magnetic field in a direction normal to the field, and the beam is caused thereby to follow an arcuate path wherein the ions of the heavier isotope tend to concentrate in the region adjacent the outer periphery. From geometric considerations there results a substantial focusing of ions of the same isotope after approximately of travel, and selective collection of isotopes may be made at this location.

The present invention relates more particularly to the evacuated vessel employed in an improved calutron and the means employed therein to assure adequate heating or baking out of the vessel during initial evacuation as well as subsequent cooling during operation. Furthermore, the present case relates to an improved door or face plate associated with the evacuated vessel having improved characteristics.

Accordingly, it is one object of the present invention to improve the speed and efficiency of baking out a calutron vessel upon initial evacuation.

It is a further object of this invention to improve the cooling facilities of a calutron during operation.

It is a further object of this invention to provide a removable door or face plate associated with such a calutron vessel which is lighter and more economical to build than previous devices, yet which has inherent qualities 'of strength and stiffness sufiicient to enable it to carry the loads required.

Further objects and advantages will be apparent from the annexed specification, in which:

Figure 1 is a side elevation, partly in section, and having portions broken away for ease of description of a calutron vessel embodying the present invention;

Fig. 2 is an enlarged section taken on the line 22 of Fig. 1;

Fig. 3 is an enlarged section taken on the line 3--3 of Fig. l; and

Fig. 4 is an enlarged section taken on the line 4- -4 of Fig. 1.

Referring more particularly to the drawings, there is disclosed a calutron tank or vessel 10 designed to be posi tioned vertically between the poles of anelectromagnet (not shown). The tank 10 rests upon posts 11 and is supported thereby. The tank is a rectangular, box-like vessel having a top wall 12, a bottom wall 13, a front door or face plate 14, a rear wall 15 and a pair of side walls 16.

The tank 10 is designed to permit circulation through suitable channels of heating or cooling fluid to assist in cooling the unit during operation thereof or alternatively to assist in heating the unit during the initial baking out period during which a high degree of vacuum, preferably of the order of 10- or 10- mm. Hg, is established within the tank. To this end the sidewalls 16 of the tank 10 comprise a main wall 17 of relatively thick steel plate to which are welded relatively thin strips 18. Over the thin strips 18 are plug welded thin sheets 19 which serve to form, together with the strips 18, a plurality of elongated channels 20. A 3" plate 21 having channels 22 and 23 therein is positioned adjacent the top edge of the Wall 17 and closes off the channels 20. A similar plate 27 is located adjacent the bottom edge of the wall 17. A plurality of 1" plugs 24 are spotted in the space 25 between the ends of the strips 18 and the plate 21 or the plate 27, and serve to bafiie or break up the flow of the circulating fluid. Similarly, adjacent the upper and lower ends of the strips 18 are positioned 1" plugs 26.

The circulating fluid is supplied through inlet pipe 30 from which a pair of pipes 31 lead to the headers 32 formed in part by a strip 33 welded, as at 34, to the strips 19. As shown, there are a pair of the headers 32 each communicating with the space 25.

One of the strips 18, labelled 35, is continued to contact with the plate 21 and thus causes the incoming fluid to take the path shown by the small arrows. A similar strip 36 contacts the plate 27, as shown. Headers 37, similar to the headers 32, are provided near the front of the tank through which the circulating fluid may be s w b drawn ofi, vby means of pipes 30a. Also, it will be appreciated that the other side wall is a duplicate of the one shown and described, so that in effect, each side wall has its own'built-in circulating system. 7

Various .conventional viewing windows or ports ,38 are provided in the rear. and bottom walls and a pump-down manifold39 is located as shown onthe rear wall, to which a diffusion pump and a mechanical backing pump (not shown) are in practice connectedin order, that the tank 10 may be evacuated to the desired pressure of 10- or 10 mm. Hg. v

The face plate 14 is designed to carry the source mechanism 40, the receiver mechanism 41, the;liner 42 and the framework 43 on which is mounted the removable wall supporting stan'chions .44. By this arrangement the entireoperating structure, of the unit may berwithdrawn on removal of the face plate and transferred to a suitable wash rack or servicing station.

The source mechanism forms no part of the present invention, but as shown includes a pair of mechanisms 200 by means, of which ions of the material being treated are generated and the insulators 64 support a pair of accelerating mechanisms (not shown) by means of which a pair of beams of ions are drawn from the source mechanisms 200 and caused to take arcuate paths through the liner 42 to the receivers 41 according to the underlying principles governing such calutrons in general. The liner 42 carries a pair of decelerating mechanisms (not shown) by means of which velocity in excess to that required may be taken from the ions of the beam; This acceldecel mechanism 202 forms no part of the present invention but forms the subject matter of U.S. Patent No. 2,725,478,- which was issued to Byron T. Wright, on November 29, 1955.

As indicated in Fig.2, the face plate 14comprises a relatively thick frame 45, a bowed or dished plate 46, and end pieces 47. ,Top and bottom corner posts 48 are provided-for the tank and are welded, as at 49, tothe tank walls. The face plate is designed to removably close the tank in a fluid-tight seal and the inner edges of the face plate frame have a carefully finished surface and also are provided with-.a pair of grooves carrying sealing gaskets 50. Clamps 51, one end of which carries a pin 52 adapted to enter the hole 53 and the other end of which clamps-against theouter-edge of the face plate frame, are provided for securing the face plate in place upon the tank. a r V The face plate 14,is further-provided at a'pluralit-y of locations-intermediate its end pieces 47 with transverse stiffening members 206 against which are welded aplnrality of transverseposts 208 adapted to assist in supporting the walls-16 against the collapsing force of the low pressure utilized.

Adjacent the source end, the. face plate is provided with suitabl e,insulato rs andbushings 54 for leading in and supporting't-he source controls and mechanisms. A bushing 55 is provided whichcoritrins the. high-potential leads-to the accelerating mechanisms. .Another bushing 56 contains the high-potential leads to the liner 42, and supplies the:deceleratingpotential... I i Adjacent the receiver end, the face plate carries suitable adjustment rods 57 for-operation ofthe receivers, a window 58,- and a viewing mirror operating rod 59. The receivers41 are illustrated only diagrammatically as this mechanism; per;se, forms nno part of the present invention but constitutes the subject-matter of U.S. Patent No. 2,727,152, which was issued'to Sidney W. Barnes, on December 13, 19 55. It, may be stated, however, thattthe receivers 41 each include mechanism. for trapping and de-ionizingi'ons from the beams treatedin accordance with-the underlying-principles of the;gcalutron so as, to

port the insulators 62 which in turn carry the support frames 63. The insulators, 64 which support the accelerating mechanism are secured to the support frames 63.

The upper end of the liner 42 is affixed to the sup port frames 63 carried by. the insulators 62. As shown in Fig. 1, an extension 65 of the end frame 66 of the liner 42 rests upon a plate carried by the, support frames and may be bolted or otherwise secured thereto.

Adjacent the receiver end, the face plate carries a similar A frame 71 which, throughsuppo-rt insulator .72, supports the extension 73 of the end frame 74 of the liner 42. A pipe section 75 is secured to the frames .66 .and 73 as shown, and serves as a stiffening chord for the 0 shaped liner 42.

The liner 42 is formed of a plurality of picture frame sections 76 over which, on its outer edge or are, is laid acovering of perforated copper sheet 77. The covering sheet is perforated throughout. .the length of the outer wall of the liner. except in the region of the section adjacent the receiver,,in which case the;sheet remains im; perforate. Another sheet 718, unperforated, covers {the innersideorfarc of the liner. Water circulating tubes 72 areprovidedtocool the liner and are so located within the liner that they are at all times shielded; from born; bardment by the walls of the frame sections 76, as clearly a n n.. s- 4-; i The faceplate 14 is provided at its lower end with a pair of hingepins 80, journaled in gussetplates 81 De; rea ing t am heb tt m c the e l-kliletth rQ edge thereof area pair, of hinge-brackets 82 designed to re; movably receive the hinge pins ;8,0 ;when the face plate 14 isrnounted in place. Mounted upon the top of the tank 10 isa hydraulic fkick off Sighaving a clamp 84 adapted toengage a.bracket secured to the upper end of the face plate 14 andeitherdraw it firmlyclosed in fluid-tight seal with thetank or to push the faceplate off and break the seal- This kick-ofi mechanism is nopart of the present invention .and formsthe subject matter of the copending application of Roland E. Andrews, Serial No. 657,636, filed March 28, 1946, now U.S. Patent No. 2,871,363 issued January 27, 1959. I h From the foregoing description, it will be apparent that there is provided a calutroin the v ssel'or which is pro: vided with a jacket in close heat-exchange relation to the side walls thereof which can be utilized for the passage ofv'larm water or steam during baking out or for the passage ofair or cold water for cooling purposes.

Furthermore, it will be apparent that there is provided a calutron having a removable cover plate, which by reason of its being fabricated of a rectangular frame member to which is welded a bowed or dished plate of 7 thin steel, reinforced with transverse stiffening ribs, is

light and economical to fabricate yet has the necessary inherent stiffness and strength to support the entire load of thesource mechanisms, liner, receiver mechanisms and the-associated frames and brackets. I

While there has been described what is presently considered 'a preferred embodiment ofthe present invention, it will be understood that various changes and modifications may be made therein without departing from the scope of the invention and it is intended to cover all such changes and modifications as come within the true scope and spirit of the appended claims.

What is claimed is: p

1, A .calutron tank for operation under high vacuum conditions comprising in combination, a pair of massive side walls adapted to be disposedin closely spaced relation to magnet pole faces and providing s upportfor the remaining tank walls, one of said latter walls comprising a pivoted; door movable between saidp'ole faces in a vertical plane and adapted to support a cantilever mounted load in addition to the vacuum load, sealing means interposed between said door and the cooperating walls of said tank, said door having a rectangular frame portion mounting a relatively thin outwardly convex plate section and provided with transverse stiffening members to which said cantilever load is attached.

2. A calutron tank for operation under high vacuum conditions comprising in combination, a pair of massive side walls adapted to be disposed in closely spaced relation to magnet pole faces and providing support for the remaining tank walls, one of said latter walls comprising a rectangular frame, an outwardly convex plate mounted within said frame, a plurality of transverse stiffening members mounted on said plate to support a cantilever mounted load, a sealing gasket mounted on the face of said frame adjacent the cooperating walls of said tank, and pivot means mounted between one side of said frame and the corresponding wall of said tank.

3. A calutron tank for operation under high vacuum conditions comprising in combination, a pair of massive side walls adapted to be disposed in closely spaced relation to magnet pole faces and providing support for the remaining tank walls, one of said latter walls comprising a rectangular frame having a face thereof adapted to abut against cooperating walls of said tank, sealing means disposed between said frame face and said cooperating walls, a relatively thin curved plate mounted within said frame, the curvature of said plate extending outwardly from said tank, a plurality of stiffening members transversely mounted on said plate to provide strength to said plate against the vacuum load and to support a cantilever mounted load, and a plurality of pivot means mounted between one side of said frame and the corresponding side of said tank.

References Cited in the file of this patent UNITED STATES PATENTS 378,359 Enos Feb. 21, 1888 1,664,972 Dudderar Apr. 3, 1928 1,686,831 Matchette Oct. 9, 1928 1,930,366 Matchette Oct. 10, 1933 2,070,499 Treanor Feb. 9, 1937 2,113,776 Smith Apr. 12, 1938 2,185,373 George Ian. 2, 1940 2,267,769 Von Ardenne Dec. 30, 1941 

